The ever increasing volume of mail received and processed on a daily basis by many businesses has, in many instances, made manual handling of individual pieces extremely costly and inefficient. The combination of increased volume of mail and rising labor costs created a demand which lead to the development of various mechanized mail and document processing and handling systems. For example, U.S. Pat. No. 5,147,169 to Miller, et al. discloses an automated envelope handling system including a pair of vacuum manifolds positioned on the opposite sides of an envelope travel path to separate the envelope folds. U.S. Pat. No. 4,909,021 to Barbour discloses an automated envelope opener that employs a an envelope opening mechanism for opening a specially designed envelope. The envelope includes slits which allow extracting "fingers" to enter the envelope during the opening process and free a flap in the return address portion of the envelope.
U.S. Pat. No. 4,893,454 to Russell discloses an envelope opening machine that opens three sides of an envelope, leaving the unopened edge in a generally downward position. The machine incorporates opposed elongate folder blades for closing upon the side panels of the envelope and an opposed pair of elongate grasping members including suction cups for engaging opposed panels of the envelope. U.S. Pat. No. 4,373,848 to Bishop discloses an apparatus for exposing contents of an opened envelope with gravity assist. U.S. Pat. No. 4,233,800 to Long, et al. discloses an envelope opener including a peel back station for peeling back the top panel of an envelope to expose the contents of the envelope. U.S. Pat. No. 4,142,430 to Long, et al. also discloses an envelope opener employing a peel back station for peeling back the top panel of an envelope to expose the contents thereof.
U.S. Pat. No. 3,384,252 to West discloses an apparatus for extracting items from envelopes including suction members for engaging the sides of a previously severed envelope. U.S. Pat. No. 3,238,926 to Huck discloses an envelope opening machine that opens a previously severed envelope by transporting it past suction means which cause the top leaf of the envelope to lay back. U.S. Pat. No. 3,143,100 to Krupotich discloses an unfolding mechanism including a mechano-pneumatic envelope opening apparatus in which shiftable envelope engaging heads pneumatically attract the opposite sides of an envelope.
However, none of the foregoing patents provide a mechanism consisting of an apparatus for unfolding a bifolded mailpiece after the edges of the mailpiece have been opened.